Running and Ageing

Posted on August 15, 2008 by



ScienceDaily (Aug. 11, 2008) – Regular running slows the effects of
aging, according to a new study from Stanford University School of
Medicine that has tracked 500 older runners for more than 20 years.
Elderly runners have fewer disabilities, a longer span of active life
and are half as likely as aging non-runners to die early deaths, the
research found.

“The study has a very pro-exercise message,” said James Fries, MD, an
emeritus professor of medicine at the medical school and the study’s
senior author. “If you had to pick one thing to make people healthier as
they age, it would be aerobic exercise.” The new findings will appear in
the Aug. 11 issue of the journal Archives of Internal Medicine.

When Fries and his team began this research in 1984, many scientists
thought vigorous exercise would do older folks more harm than good. Some
feared the long-term effect of the then-new jogging craze would be
floods of orthopedic injuries, with older runners permanently hobbled by
their exercise habit. Fries had a different hypothesis: he thought
regular exercise would extend high-quality, disability-free life.
Keeping the body moving, he speculated, wouldn’t necessarily extend
longevity, but it would compress the period at the end of life when
people couldn’t carry out daily tasks on their own. That idea came to be
known as “the compression of morbidity theory.”

Fries’ team began tracking 538 runners over age 50, comparing them to a
similar group of non-runners. The subjects, now in their 70s and 80s,
have answered yearly questionnaires about their ability to perform
everyday activities such as walking, dressing and grooming, getting out
of a chair and gripping objects. The researchers have used national
death records to learn which participants died, and why. Nineteen years
into the study, 34 percent of the non-runners had died, compared to only
15 percent of the runners.

At the beginning of the study, the runners ran an average of about four
hours a week. After 21 years, their running time declined to an average
of 76 minutes per week, but they were still seeing health benefits from
running.

On average both groups in the study became more disabled after 21 years
of aging, but for runners the onset of disability started later.

“Runners’ initial disability was 16 years later than non-runners, ‘”
Fries said. “By and large, the runners have stayed healthy.”

Not only did running delay disability, but the gap between runners’ and
non-runners’ abilities got bigger with time.

“We did not expect this,” Fries said, noting that the increasing gap
between the groups has been apparent for several years now. “The health
benefits of exercise are greater than we thought.”

Fries was surprised the gap between runners and non-runners continues to
widen even as his subjects entered their ninth decade of life. The
effect was probably due to runners’ greater lean body mass and healthier
habits in general, he said. “We don’t think this effect can go on
forever,” Fries added. “We know that deaths come one to a customer.
Eventually we will have a 100 percent mortality rate in both groups.”

But so far, the effect of running on delaying death has also been more
dramatic than the scientists expected. Not surprisingly, running has
slowed cardiovascular deaths. However, it has also been associated with
fewer early deaths from cancer, neurological disease, infections and
other causes.

And the dire injury predictions other scientists made for runners have
fallen completely flat. Fries and his colleagues published a companion
paper in the August issue of the American Journal of Preventive Medicine
showing running was not associated with greater rates of osteoarthritis
in their elderly runners. Runners also do not require more total knee
replacements than non-runners, Fries said.

“Running straight ahead without pain is not harmful,” he said, adding
that running seems safer for the joints than high-impact sports such as
football, or unnatural motions like standing en pointe in ballet.

“When we first began, there was skepticism about our ideas,” Fries said.
“Now, many other findings go in the same direction.”

Fries, 69, takes his own advice on aging: he’s an accomplished runner,
mountaineer and outdoor adventurer.

Hanging on his office wall is a photo he jokingly describes as “me,
running around the world in two minutes.” In the dazzling image of blue
sky and white ice, Fries makes a tiny lap around the North Pole.

Fries collaborated with Stanford colleagues Eliza Chakravarty, MD, MS,
an assistant professor of medicine; Helen Hubert, PhD, a researcher now
retired from Stanford, and Vijaya Lingala, PhD, a research software
developer.

The research was supported by grants from the National Institute of
Arthritis and Musculoskeletal and Skin Diseases and by the National
Institute on Aging.

Journal reference:

1. Eliza F. Chakravarty, MD, MS; Helen B. Hubert, PhD; Vijaya B.
Lingala, PhD; James F. Fries, MD. Reduced Disability and Mortality Among
Aging Runners: A 21-Year Longitudinal Study. Archives of Internal
Medicine, 2008; 168 (15): 1638 DOI: 10.1001/archinte. 168.15.1638

Adapted from materials provided by Stanford University Medical Center.

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